Mixed fluid delivery system

ABSTRACT

An apparatus and method for operating and calibrating a paint mixture delivery system includes a positive displacement fluid cylinder and a linear transducer that monitors operation of the positive displacement fluid cylinder. A controller is connected to a servo drive whose operation manipulates the performance of the positive displacement fluid cylinder. Operation of the fluid delivery system is controlled such that the ratio of paint or resin to catalyst or hardener can be accurately controlled and calibration of the discrete fluid flow sensors can be quickly and conveniently calibrated to assure delivery of the respective fluids are the desired mixture ratio.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a divisional patent application that claims priority to U.S.patent application Ser. No. 13/444,668 filed on Apr. 11, 2012 titled“Mixed Fluid Delivery System” and which claims priority to U.S.Provisional Patent Application Ser. No. 61/474,828 filed on Apr. 13,2011 titled “Mixed Fluid Delivery System” and the disclosures of whichare expressly incorporated herein.

BACKGROUND OF THE INVENTION

In spray paint operations, a paint fluid or resin, commonly in the formof a liquid, is mixed with one or more constituents, such as hardenersand/or liquid or solid color additives, prior to application of themixed material to a work surface. Commonly, the user must eithermanually mix the constituents prior to application of the final mixtureand/or provide a metered introduction of the constituents into a fluidflow to attain a desired mixture. The repeatability of generating agiven fluid mixture is substantially limited by the ability of atechnician to repeatedly measure and combine the constituent fluids andadditives in an accurate manner to produce the desired mixture.Additionally, the consistent attention to the operation of the discretesystems of the mixed fluid delivery system requires a highly skilled ortrained operator to ensure repeatable desired results during eachmaterial application cycle.

Automatic mixing devices overcome some of the shortcomings associatedwith manual mixing requirements but present their own drawbacks. FIGS.3-5 show an exemplary prior art two-part fluid delivery system or fluidmixing machine that adds a catalyst or a hardener to a fluid paintstream. Such mixing machines are widely used during the coating orpainting of various metal, carbon or fiber, or plastic based materialparts commonly configured as automotive or vehicle body panels and thelike.

In the automotive environment, such parts are most often finished withwhat is commonly understood as low bake temperature coatings. Prior tothe advent of automatic mixing machines, a finisher or paint applicatorpersonnel would manually add hardener to the resin or paint in a batchform and attempt to utilize the batch before expiration of the usable orpot-life of the mixture. Such pre-application preparation of the mixturerequires an estimation of the total material needed to treat or coat allof the desired parts. Such activity commonly requires the personnel toestimate both fluid material consumption as well as the amount ofmaterial that the given operator can consume within the duration or potlife of the particular material mixture.

Depending on a number of commonly understood parameters includingambient temperature and humidity, constituent composition and ratios,desired product characteristics, substrate conditions, etc., the ratioof hardener to color fluid, resin or paint can commonly vary from ratiosof 1:1 to less than 100:1. Such bulk batching commonly results insubstantial waste with operators mixing more than adequate amounts ofmaterial to avoid “running short” or consuming all of thepre-application mixed material before all of the desired parts have beentreated.

With the variable desired ratio ranges, ratio repeatability is typicallyonly about 5% and incorrect ratios can result in complications and/orinoperability of the paint system during application of the colormixture or a less than desired and/or acceptable finished or cured paintlayer. If insufficient hardener or catalyst is added to the fluid paint,the paint mixture will normally not dry or cure as desired. Excessivehardener or catalyst detrimentally impacts pot-life and can also yieldundesirable or unacceptable finish part quality. Such complicationscommonly result in requiring that the affected parts be cleaned andretreated or repainted and/or discarded altogether. Unexpected pot-lifelimits can also detrimentally affect and/or damage the operability ofthe material applicator devices.

Many automatic mixing devices commonly use multiple electro-mechanicalflow meters that monitor the individual volumes of paint or resin andhardener for ratio assurance. Such flow meters are commonly provided astwo meshed gears that turn freely in the respective fluid flow. A geartooth sensor monitors movement of the teeth of a respective gear toassess the fluid flow. Each tooth represents a specific volume. Anexemplary standard volume per gear tooth is 0.12 cc/gear tooth.Understandably, other volume flow meters are available for otherapplications.

Many paints or resins and hardeners are relatively thin or have lowfluid viscosities such that, even with the relatively close mechanicalassociation of the gears and the corresponding housing of such flowmeters, some of the fluid material can pass around and/or through thegears in a manner that detracts from the accuracy of the respectivefluid measurement. Low relative fluid flow rates can also exacerbate theability to accurately assess the respective fluid flow. Accordingly,such fluid delivery systems must be diligently monitored and/orfrequently calibrated to ensure accurate assessment and monitoring ofthe respective constituent fluid material flows. Although frequentsystem calibration reduces the potential for inaccurate operation of therespective flow meters, repeated calibration of the flow sensor detractsfrom the “automatic” nature of such fluid delivery systems and wastesboth operating time and materials.

Calibration of such automatic fluid delivery systems commonly requires amultiple step verification process. FIGS. 3-5 show an exemplary priorart automatic paint application system. During a combined fluid flowverification process, the operator must verify the volume of the paint,resin flow, and combined volume to assess the operability of the system.As shown in FIG. 3, in first step of assessing operation of the systemthe operator draws a sample from a designated port 20 into a graduatedcylinder or beaker 22. The value of the measured volume is entered intoa controller 24.

Referring to FIG. 4, this fluid measuring process is then repeated forthe additive or hardener fluid path of the fluid mixing system. As shownin FIG. 4, the delivery system includes a second designated port 30 thatis in fluid communication with a hardener fluid flow path. A hardenersample is acquired with another graduated cylinder 32 such that thevolume of hardener delivered can also be determined or assessed.Controller 24 is in communication with a pair of toothed gear flowmeters 38, 40 that electro-mechanically assess the flow of therestrictive additive and resin flows in the manner described above.These values are communicated to controller 24 as the detected flowvalues. The value of the acquired volumes of hardener and resin areentered into controller 24 which thereby compares the discrete measuredvolumes with the discrete detected flow values to calibrate therespective flow meter 38, 40 associated with delivery of the respectivehardener and resin materials.

After the individual flow meters 38, 40 have been calibrated, the fluidmaterial delivery ratio can be assessed. Referring to FIG. 5, to verifythe delivery ratio between the paint material and/or resin and thehardener, the user uses two beakers 34, 36 during concurrent delivery ofboth the paint and/or resin fluid and the liquid hardener duringoperation of the delivery system. The two constituents or fluidcomponents flow concurrently into separate beakers 34, 36. Visualinspection of beakers 34, 36 allows the user to visually and thenmathematically verify the ratio between the delivery of the paint and/orresin and the hardener. After each calibration process, the user mustclear or clean the dedicated sample ports 20, 30 as well as the variouscylinders 22, 32, 34, 36 associated with the acquisition of the varioussamples.

The calibration and delivery ratio verification process is cumbersomeand time consuming and includes such drawbacks that many users neglectto perform the operational verification processes. As alluded to above,neglecting confirmation of the operational integrity of the paintdelivery system can result in less than desired, unexpected, and/orunacceptable constituent fluid deliver performance and yield potentiallyunacceptable part or application quality as well as possible damage tothe underlying paint application system. Although hindering operation ofthe application system until completion of an operational verificationprocess would result in more timely completion of the verificationcalibration (if not bypassed), mandating such verification does notresolve the inefficiencies associated with the manual verification andcalibration of the various sensors and volume assessments.

Therefore, there is a need for a mixed fluid delivery system that bothaccurately delivers desired amounts of constituent fluids and can bequickly and conveniently assessed to verify the operational integrity ofthe fluid delivery system with respect to preset operating conditions.

BRIEF DESCRIPTION OF THE INVENTION

The present invention provides a mixed fluid delivery system thatovercomes one or more of the aforementioned drawbacks. One aspect of theinvention discloses an apparatus and method for operating andcalibrating a paint mixture delivery system. The delivery systemincludes at least one positive displacement fluid cylinder and a lineartransducer that monitors operation of the positive displacement fluidcylinder. A controller is connected to a servo drive whose operationmanipulates the performance of the positive displacement fluid cylinder.Operation of the fluid delivery system is controlled such that the ratioof paint or resin to catalyst or hardener can be accurately controlledand calibration of the discrete fluid flow sensors can be quickly andconveniently calibrated to assure delivery of the respective fluids atan acceptable desired mixture ratio.

Another aspect of the invention disclosed a mixed fluid paint deliverysystem having a cylinder type catalyst flow pump constructed tointroduce an amount of a catalyst to a resin flow. A transducer isconfigured to monitor operation of the cylinder type catalyst flow pumpand a controller is connected to the transducer and configured todetermine a resin flow and manipulate operation of the cylinder typecatalyst flow pump to provide a resin and catalyst mixture having adesired resin to catalyst ratio.

Another aspect of the invention discloses a paint delivery system havinga first inlet that is connectable to a paint resin source and a secondinlet connectable to an additive to be added to a flow of paint resin toform a paint mixture deliverable to an applicator. The paint deliverysystem includes a linear pump that is connected to one of the firstinlet and the second inlet and a controller that is configured tomonitor operation of the linear pump and control flow from the firstinlet and the second inlet to maintain a desired ratio of constituentsin the paint mixture at the applicator.

Another aspect of the invention includes a method of calibrating a paintmixture delivery system. The method includes communicating a mixturethat includes a resin and an additive to a container. A resin flow isdetermined by subtracting a measured additive flow volume measured witha linear transducer from a volume of the container after communicationof the mixture thereto. The determined resin flow is compared to ameasured resin flow and a resin flow meter calibration is adjusted froma current condition if the determined resin flow varies more than anacceptable deviation from the calculated resin flow.

These and other aspects and features of the invention summarized aboveare not limited to any one particular embodiment of the invention. Thatis, many or all of the aspects above may be achieved with any particularembodiment of the invention. Those skilled in the art will appreciatethat the invention may be embodied in a manner preferential to oneaspect or group of aspects and advantages as taught herein. These andvarious other aspects, features, and advantages of the present inventionwill be made apparent from the following detailed description and thedrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings illustrate preferred embodiments presently contemplated forcarrying out the invention.

FIG. 1 is an elevation view of a dual fluid delivery system according tothe present invention;

FIG. 2 is a flow chart showing a calibration sequence associated withconfirming desired operation of the fluid delivery system shown in FIG.1;

FIG. 3 is a view similar to FIG. 1 of a prior art paint delivery system;

FIG. 4 is a view similar to FIG. 3 and shows a second step of acalibration process associated with assessing operation of the paintdelivery system; and

FIG. 5 is a view similar to FIG. 3 and shows a third step of thecalibration process associated with assessing operation of the paintdelivery system.

In describing the preferred embodiment of the invention which isillustrated in the drawings, specific terminology is resorted to for thesake of clarity. However, it is not intended that the invention belimited to the specific terms so selected and it is to be understoodthat each specific term includes all technical equivalents which operatein a similar manner to accomplish a similar purpose. For example, theword connected or terms similar thereto are often used. Such terms arenot limited to direct connection but include connection through otherelements where such connection is recognized as being equivalent bythose skilled in the art.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 shows a mixed fluid delivery system 100 according to a preferredembodiment of the present invention. Unlike the mixed fluid deliverysystem shown in FIGS. 3-5, which includes like pump and sensorassemblies associated with moving each of the respective fluid materialsthrough the system, system 100 includes a servo driven positivedisplacement cylinder 102 that pumps the catalyst or hardener from abulk supply or source 104. Delivery system 100 is configured to deliverconstituent composition and ratios of catalyst or hardener to colorfluid, resin or paint that can vary between 0:1 to 500:1 and cancommonly vary from ratios of 1:1 to less than 100:1. Displacementcylinder 102 eliminates the detriments attributable to slip common togear flow monitoring devices and which is particularly problematic atlow flows and when used with low viscosity fluids. As explained furtherbelow, displacement cylinder 102 allows system 100 to maintain operationat higher resin to catalyst ratios and improves the accuracy with whichthe operation of system 100 can be monitored.

Cylinder 102 is equipped with a linear transducer 106 that measures themovement of a piston 108 associated with the cylinder. Transducer 106 iselectrically connected to a controller 110 that assesses the signal oftransducer 106 to monitor the travel distance of piston 108, andtherefrom, to calculate a volume of material associated with theoperation of the cylinder as can be calculated from the longitudinaltravel of the piston as it relates to the cross-sectional area ofcylinder 102. Controller 110 is preferably a programmable logiccontroller such as those commonly available from Allen Bradley but it isappreciated that any number controls, control devices, or simplycontrollers can be configured for operation and monitoring of system100. Preferably, controller 110 is configured to receive a number ofinput signals from various devices such as sensors and/or pumps ofsystem 100 and generate a one or more outputs that can be directed tothe same or different devices to manipulate the operation of the same.

It is further appreciated that controller 110 include one or more inputs118, 120, 122 in the form of switches and/or buttons that are configuredto be manipulated by an operator to interact with controller 110 andthereby interfere and/or manipulate operation of system 100. It isappreciated that the user can input a value associated with attaining adesired ratio of resin to additive at the applicator or applicationdevice 114 during operation of system 100. As explained above, suchratios can be determined by parts being coated, resin and additivecompositions, desired cure parameters, etc. It is further appreciatedthat controller 110 can include an optional output, indicator, ordisplay 124 configured to communicate information regarding theoperation of system 100 to a user. It is appreciated that the modalityof the information associated with the output of display 124 can be oneor more of audible, visual, or tactile, or electrically to anotherdevice configured to generate similar outputs for communicatinginformation to the user as to the instantaneous or changes to any of thesensor or flow manipulating systems of system 100. It is appreciatedthat the one or more inputs and outputs associated with the operation ofcontroller 110 can be used to generate wholly automatic operation of thesystem when a user may or may not be provided an alert as to a change inthe operating condition or could be required to initiate a response tothe respective input/output signal, such as manipulating a valve,switch, dial, or button to provide semi-automatic operation of thesystem or operation that requires user interaction.

Resin material, such as paint, is communicated to system 100 from asource 112. The resin and hardener or catalyst are delivered to mixingsystem 100, mixed and subsequently communicated to one or moreapplicators or application devices 114, such as a paint gun. Paint gun114 is commonly understood to be connected to an air flow or gas source125 and constructed such that when the mixed fluid is delivered to thegun, and a trigger 126 is activated, a highly atomized flow of paint 128is expelled or sprayed from the gun in a controlled manner in anapplication direction. It is appreciated that system 100 can deliver oneor more fluid streams at the same or different operating specificationsto allow concurrent utilization of system 100 for different parts or theapplication of a uniform material to different or simply larger unitaryparts and/or assemblies. It is further appreciated that should any ofthe respective delivery or pump systems of system 100 require an airflow for operation, system 100 can also be fluidly connected to airsource 125 either in series or parallel with applicator 114. It isappreciated that flow of paint 128 can be manipulated by manipulation ofboth the air flow associated with source 124 and the tip orientation andstructure of application device 114.

A flow meter or sensor 132, such as a gear-type flow meter as discussedabove, monitors the flow of resin communicated through system 100. Asthe volume of the resin flow is generally higher than any other additiveor catalyst flow, gear type flow meters can be adequately calibrated toassess the resin flow within an acceptable degree of inaccuracyassociated with paint applications but the paint or resin flow cannonetheless be calibrated in the manner discussed further below. It isfurther appreciated that flow meter or sensor 132 could be replaced withthe cylinder and transducer pair. It is appreciated that thecross-sectional stroke of such a configuration could be manipulated toapproach the ratio of the respective fluid.

System 100 also includes a solvent inlet 136 that is fluidly connectedto a solvent source 138 for removal of residuals of prior materials andcleaning of applicator 114 of system 100 as is well understood in theart. It is further envisioned that system 100 include one or moreconnections and/or assemblies associated with moving the catalyst,resin, and solvent to and through the applicable portions or passages ofsystem 100. It is envisioned that such systems can include fluidspecific pumps, one or more automatically, manually, or combinationthereof of selectively operable or controlled valves, and/orpressurization of the respective sources to facilitate passage of thematerials to the respective fluid connections of system 100. It isappreciated that there are a number of modalities and configurationsassociated with communicating and/or limiting the communication of therespective fluids between sources 104, 112, 138, system 100, andapplicator 114.

Regardless of the delivery methodology, as catalyst pump or cylinder 102has no slip, unlike the fluid delivery system shown in FIGS. 3-5, fluidmixing system 100 can be calibrated and verified in a one process withonly one sample beaker and with no supplemental system outlet ports. Asexplained further below, regardless of the fluid delivery methodologyand the means of the assessing the respective fluid flows, it isenvisioned that the fluid flow calibration process as described hereincan also accurately assess the respective fluid flows for those fluidflow systems wherein the respective fluid flows are both assessed witheither separate and/or a combined gear-type fluid flow meters—commonlyreferred to a dual flow meter configuration.

Referring back to FIGS. 1 and 2, during a calibration process 150 ofsystem 100, the user merely needs to operate the system as throughapplying material but without the flow of atomization gas. The user cansuspend the flow of atomization gas or provide an instruction tocontroller 110 to suspend the atomization gas flow 152 during acalibration sequence. Preferably, the user provides a calibrateinstruction 154 to controller 110 and activates 156 trigger 126 ofapplicator 114 while directing non-atomized but mixed material 128 intoa measuring device such as a graduated cylinder 140.

During collection of the measured sample, controller 110 monitors thetotal fluid flow as determined by the combined assessment of theoperation of cylinder 102 and transducer 106 and sensor 132. The userthen enters a value of the measured flow 158, which includes resin andadditive, into controller 110. Controller 110 then compares 160 themeasured flow value 158, as determined by graduated cylinder 140, to thecalculated value, as determined as by the desired ratio and operation ofcylinder 102 and transducer 106 and resin flow sensor 132.

If the calculated volume value and the measured volume value informationare within an acceptable deviation of the desired ratio of operation ofthe paint delivery system, integrity of system 100 has been confirmedand, with the introduction of the atomization gas and completion of thecalibration sequence, system 100 is configured for operation. If thecalculated volume value is greater than or less than the measured volumevalue, or a tolerable deviation associated with the same, such anindication, based on the reliability of the accuracy of cylinder 102 andtransducer 106, indicates an unacceptable calibration of resin gear typeflow sensor 132.

During such an event, controller 110 assigns a new value 162 to theoperation of sensor 132 to yield delivery of a mixed fluid material thatis within an acceptable range of the desired or expected mixture ratio.That is, since the volume of the additive, catalyst or hardener is knownas a function of the construction and operation of cylinder 102, thevolume or value of the resin material flow can be mathematicallycalculated by controller 110 as the value of the total volume acquiredin beaker 140, as entered into controller 110 by the user, minus thevolume of material delivered by cylinder 102, as communicated/determinedby controller 110 via communication with transducer 106.

Preferably, system 100 will tolerate sensor operation and thereby ratiodeviations from the desired ratio for those ratio ranges that are knownto yield parts of acceptable quality. In a similar manner, system 100may suspend operation of the system and/or manipulate the operation ofsensor 132 and thereby the respective flow associated therewith if thecalculated ratio is beyond desired thresholds or if the measured ratiois incapable of producing acceptable finish parts. If system 100 hasconfirmed the accuracy of operation of sensor 132, or adjusted the valueassociated with the operation of sensor 132, the user can confirm theefficacy of the calibration via repeating of sequence 150, or proceed totreatment of parts with the simple reintroduction of the atomization gasflow. That is, after calibration sequence 150, system 100 is ready fornear immediate operation. System 100 allows the user to quickly andaccurately assess the operation of system 100 with limited waste and inan efficient manner. The ease and efficiency of the ratio check andconfirmation increases the likelihood that users will more periodicallyassess the operability of system 100.

As alluded to above, the calibration verification associated withprocess 150 is also usable with dual flow control systems with theacquisition of a single sample unlike the process associated with thesystems shown in FIGS. 3-5. During such a process, controller 110 isconfigured to record the two volumes as assessed with the respectiveflow meters. Controller 110 then displays the total recorded volumeassociated with the sample acquisition duration. A user can then performthe comparison of the measured volume to the displayed volume or enterthe measured volume into controller 110 if the measured volume is notthe same as the recorded and displayed volume. If the measured volume isthe same or within a tolerable range or deviation from the recordedvolume, the user has verified calibration of the respective flow meters.If the measured and the recorded values are not within a tolerable oracceptable range, controller 110 can be configured to manipulate thevalue of one or both of the outputs of the respective flow meters, mostlikely the catalyst flow value for the reasons discussed in thebackground of the application, thereby achieving calibration of theunderlying fluid delivery system. It is appreciated that such a singlestep calibration verification would result in less waste as more as ahigher likelihood that technicians and/or users will perform thecalibration and calibration verification processes regardless of thespecific configuration of the underlying fluid connections, valves, andnumber of applicators associated with the respective fluid deliverysystem.

Therefore, one embodiment of the invention includes a mixed fluid paintdelivery system having a cylinder type catalyst flow pump constructed tointroduce an amount of a catalyst to a resin flow. A transducer isconfigured to monitor operation of the cylinder type catalyst flow pumpand a controller is connected to the transducer and configured todetermine a resin flow and manipulate operation of the cylinder typecatalyst flow pump to provide a resin and catalyst mixture having adesired resin to catalyst ratio.

Another embodiment of the invention includes a paint delivery systemhaving a first inlet that is connectable to a paint resin source and asecond inlet connectable to an additive to be added to a flow of paintresin to form a paint mixture deliverable to an applicator. The paintdelivery system includes a linear pump that is connected to one of thefirst inlet and the second inlet and a controller that is configured tomonitor operation of the linear pump and control flow from the firstinlet and the second inlet to maintain a desired ratio of constituentsin the paint mixture at the applicator.

Another embodiment of the invention includes a method of calibrating apaint mixture delivery system. The method includes communicating amixture that includes a resin and an additive to a container. A resinflow is determined by subtracting a measured additive flow volumemeasured with a linear transducer from a volume of the container aftercommunication of the mixture thereto. The determined resin flow iscompared to a measured resin flow and a resin flow meter calibration isadjusted from a current condition if the determined resin flow variesmore than an acceptable deviation from the calculated resin flow.

Of course, specific details of the preferred embodiment as describedherein are not to be interpreted as limiting the scope of the invention,but are provided merely as a basis for the claims and for teaching oneskilled in the art to variously practice and construct the presentinvention in any appropriate manner. Changes may be made in the detailsof the construction of various components of the delivery system withoutdeparting from the spirit of the invention especially as defined in thefollowing claims.

What is claimed is:
 1. A paint delivery system comprising: a first inletconnectable to a paint resin source; a second inlet connectable to anadditive to be added to a flow of paint resin to form a paint mixturedeliverable to an applicator; a linear pump connected to one of thefirst inlet and the second inlet; and a controller configured to monitoroperation of the linear pump and control flow from the first inlet andthe second inlet to maintain a desired ratio of constituents in thepaint mixture at the applicator.
 2. The paint delivery system of claim 1further comprising a flow meter exposed to the flow of paint resin priorto addition of the additive.
 3. The paint delivery system of claim 2wherein the controller is configured to manipulate calibration of theflow meter in response to a comparison of a measured volume of a paintmixture delivered to the applicator and an assessment of operation ofthe linear pump for a given duration.
 4. The paint delivery system ofclaim 3 further comprising a third inlet connectable to a solvent sourcefor communicating a solvent through those portions of the paint deliverysystem associated with the flow of paint resin.
 5. The paint deliverysystem of claim 3 wherein at least one of a valve and the controller isconfigured to suspend communication of an atomizing fluid to theapplicator during acquisition of the measured volume.
 6. The paintdelivery system of claim 5 further comprising at least one inputconnected to the controller and configured to allow a user to interactwith the controller.
 7. The paint delivery system of claim 1 wherein thedesired ratio of constituents is adjustable between ratios of resin tocatalyst between 0:1 to 500:1.
 8. The paint delivery system of claim 1wherein the controller is further configured to determine an amount ofresin from a user input of a sample volume minus a flow value associatedwith operation of the linear pump during acquisition of the samplevolume.
 9. The paint delivery system of claim 1 further comprising apaint resin flow meter that is exposed to the flow of paint resin andelectrically connected to the controller.
 10. The paint delivery systemof claim 9 wherein the controller is configured to assign a flow valueassociate with operation of the paint resin flow meter duringcalibration of the paint resin flow meter and that is at least partlydependent on operation of the linear pump.
 11. The paint delivery systemof claim 9 wherein the paint resin flow meter is a gear type flow meter.12. A method of calibrating a paint mixture delivery system comprising:communicating a mixture that includes a resin and an additive to acontainer; determining a resin flow by subtracting a measured additiveflow volume measured with a linear transducer from a volume of thecontainer after communication of the mixture thereto; comparing thedetermined resin flow to a measured resin flow; and semi-automaticallyor automatically altering a resin flow meter calibration from a currentcondition if the determined resin flow varies more than an acceptabledeviation from the calculated resin flow.
 13. The method of claim 12wherein the measured additive flow volume further comprises associatingthe linear transducer with a positive displacement cylinder.
 14. Themethod of claim 13 further comprising driving the displacement cylinderwith a servo-drive whose operation is controlled by a controller. 15.The method of claim 14 further comprising measuring the volume of thecontainer and entering the measured volume into the controller.
 16. Themethod of claim 14 further comprising setting a desired resin toadditive ratio by entering a ratio value into the controller prior tocommunicating the mixture to the container.
 17. The method of claim 14wherein communicating the mixture to a container further comprisesactuating a spray gun to communicate the mixture through the spray gunwithout an atomizing gas.
 18. The method of claim 14 further comprisingentering a desired resin to additive ratio into the controller prior tocommunicating the mixture to the container.